LED light units are becoming more and more common in many fields of technology. In the exemplary field of passenger transport vehicles, such as aircraft, road vehicles, ships or rail cars, more and more interior and exterior lights are based on LED technology. Such LED light units are commonly designed for a particular power consumption and, accordingly, for a particular power reception from the power supply. However, this power reception may not always be stationary over time. In particular, if one of the LEDs breaks, a situation may arise where the LED light unit becomes defective and does not collect any power from the power supply. It is also possible that the power consumption of the LED light unit increases over time in order to provide more current to the LEDs in order to keep the output light intensity constant despite ageing of the LEDs. These changes in the functioning of the LED light unit are an important piece of information for the overall passenger transport vehicle. In particular, this information would be useful to have for a maintenance computer of the passenger transport vehicle, such as an aircraft maintenance computer or car maintenance computer. In prior art approaches, no satisfactory system for conveying said information has been proposed.
Accordingly, it would be beneficial to provide a light unit based on LED technology that has improved means for conveying information about its operational status to the remainder of the passenger transport vehicle, in particular to the remainder of the power supply system. Further, it would be beneficial to provide a passenger transport vehicle, in particular an aircraft, with such improved light unit based on LED technology. Further, it would be beneficial to provide a method of replacing existing light units with such improved light units.